1. Field of the Invention
The present invention relates to 5-[(4-N,N-ditolylamino)benzyl]-5H-dibenzo[a,d]-cycloheptane derivatives which are effective as organic photoconductive materials for use in electrophotography.
2. Discussion of Background
Various organic photoconductive materials have been conventionally proposed for use in an electrophotographic process. For example, poly-N-vinylcarbazole and triphenylamine compounds are disclosed in U.S. Pat. No. 3,180,730; and benzidine compounds in U.S. Pat. No. 3,265,496, Japanese Patent Publication 39-11546 and Japanese Laid-Open Patent Application 53-27033.
In the above-mentioned electrophotographic process, the surface of a photoconductor is charged uniformly in the dark to a predetermined polarity, for instance, by corona charging. The uniformly charged photoconductor is exposed to a light image to selectively dissipate the electrical charge of the exposed areas, so that a latent electrostatic image is formed on the photoconductor. The thus formed latent electrostatic image is developed by a developer or toner to a visible image.
Fundamental characteristics required for the photoconductor in such an electrophotographic process are: (1) chargeability to an appropriate potential in the dark, (2) minimum dissipation of electrical charge in the dark, and (3) rapid dissipation of electrical charge when exposed to the light.
However, the above-mentioned conventional organic photoconductive materials do not necessarily satisfy the above characteristics at the same time.